Jack.



w. B. TEMPLETON.

JACK.

APPLICATION FILED JULY 24, 1907.

Patented June 21,1910.

2 SHEETS-SHEET 1.

B; TEMPLETON.

JAGL. APPLICATION IILED- 'JULY 24, 1907.

961,910., Patented June 21,1910.

2 SHEETS-SHEET 2.

WALTER B. TEMPLETON, OF CHICAGO, ILLINOIS.

JACK.

Specification of Letters Patent.

Patented June 21, 1910.

Application filed July 24, 1907. Serial No. 385,349.

To all whom "it may concern:

Be it known that I, WALTER B. TEMPLE.-

TON, a citizen of the United States, residing at Chicago, in the countyof Cook and State of Illinois, have invented certain new and usefulImprovements in Jacks, of which the following is a specification.

This invention relates to improvements in that class of lifting jacksdesigned for raising and lowering heavy bodies through the medium of aleverage mechanism; and more specifically it relates to that type ofjack which is double-acting; that is, in which a lifting or loweringmovement is effected by both the upward and downward movements of thelever, accordingly as the pawls are set to effect a raising or loweringof the lifting bar on the actuation of the lever arm or handle.

My present invention is in the nature of an improvement upon a jack ofthe abovementioned type forming the subject-matter of Letters Patent No.916,502, granted to me March 30, 1909; and I will first briefly describesuch features and parts as are common to the subject-matter of thatpatent and the present application, and will then more particularlypoint out the subject-matter of my present improvements.

Referring to the accompanying drawings,--Figure 1 is a side elevationalview of the complete jack. Fig. 2 is a vertical section in the plane ofthe lifting bar. Fig. 3 is a vertical section through the casing of theratchet-disk. Fig. 4 is an inside view of the cover plate for theopening in the side of the casing, showing also the leading novelfeature of the present invention consisting of a yielding or resilientguide for the pawlcontrolling pins or lugs.

Referring to the drawings, 15 designates a base-plate from which arisesa hollow u right 16 containing the usual lifting bar 1%, and havingformed on one side thereof a casing 18, and to one side of the latter alarger approximately circular casing 19, all of these parts beingpreferably formed integral or in a single casting. For convenience inassembling the parts the rear half of the edge wall of the casing 19 isformed by a sheet metal strip 20 secured in place by screws or bolts.

Journaled in suitable bearings in the outer side walls of the casings 18and 19 and coaxially with the latter, is a shaft 21, fast on whichwithin the casing 19, is a large ratchet disk 22, to one side of which,fast on the shaft 21 and engaging the teeth of the lifting bar 17, is asmaller ratchet disk 23.

In one edge of the casing 19 is an opening 24, in which is mounted onthe pivot-pin 25, the inner end of the metal socket member 26 of theusual lever arm or handle 27 of the jack. On opposite sides of the pivot25 are formed in the upper edge of the socketpiece inner and outer seats28 and 29 for a pair of pawls 30 and 31, respectively. A central rib 32on the upper edge of the socket-piece between the seats 28 and 29 servesto confine at its ends the pawls to their seats, permitting the pawls tobe inserted edgewise, the pawls being socketed or apertured suflicientlyabove their pivots opposite the ends of the rib 32 to accommodate thelatter. As will be seen by reference to Fig. 3, the pawls are sopositioned as to normally tend by gravity to fall toward and intoengagement with the periphery of the large ratchet wheel 22, which theyare designed to engage. In order, however, to insure such engagement ofthe pawls with the ratchetdisk during the lifting operation, as well asto render the same pawls capable of effecting the lowering of thelifting bar under a step by step movement, I employ a pair ofcontrolling springs with means for so tensioning said springs as tocause them to urge the pawls toward or from the ratchet disk accordinglyas the lifting bar is to be raised or lowered. To this end the pawls areprovided with laterally projecting pins or studs 33 and 34 which areapertured to receive the free ends 35 and 36 of a bent Wire spring,which latter is fulcrumed on a pivot-bolt 37 secured to the casing 19,and has its looped or doubled body portion 38 extended downwardly on theopposite side of the fulcrum and passed through a stud 39 (Fig. 1rotatably and eccentrically mounted in a isk 40, which latter in turn isrotatably mounted in a circular opening in the outer side wall of thecasing 19. The disk 40 is provided with a thumb-piece 41 formanipulating the same, one end of which is pointed, as indicated at 42,said pointed end being adapted to engage either of a pair of oppositelydisposed stop-pins 43 and 44, the former indicating the up position, andthe latter the down position of the pawls. From this it will be seenthat when the disk 40 is turned so as to throw the member 38 of thespring inwardly, or toward the shaft 21, the ends 35 and 36 of thespring which engage the pawls are likewise flexed inwardly and thereforetend to urge the pawls toward the ratchetdisk 22. .On the other hand,when the section 38 of the spring has been swung to the opposite side ofthe center of the disk 10 by turning the latter through a halfrevolution to the position indicated in Fig. 1, the members 35 and 36 ofthe spring are flexed outwardly, and tend to throw the pawls outwardlyor away from the ratchet disk 22. When the spring has been set to the upposition, the mechanism as thus far described is complete for effectingthe raising of the lifting bar. It will be Seen that since the pawls 30and 31 are both pivoted on the lever arm but on opposite sides of thepivotal axis thereof, the upward or downward swing of said lever armtends to raise one of said pawls at the same time that it lowers theother for a fresh hold on the ratchet disk; the pawls engaging the teethof the ratchet disk as soon as permitted by virtue both of gravity andthe springs, and

on their return movements sliding off the backs of the ratchet teeth,which they tend to hug closely.

For controlling the pawls during the lowering operation of the liftingbar, at which time the springs are flexed in a direction to urge thepawls away from the ratchet disk 22, as indicated in Fig. 1, I havedisclosed in my Letters Patent above referred to a removable platecovering an opening in the side wall of the casing 19, which plate hasapertures formed therethrough through which the pins or studs 33 and 34project, which apertures have cam-shaped edges that serve to positivelydirect and guide the pawls (through the pins) alternately intoengagement with the ratchet disk in opposition to the outward thrust ofthe springs; such positive inward direction of the pawls producing therequisite alternate dogging action of the pawls during the loweringoperation. I have found in practice that, while this construction givessatisfactory results in most instances, yet occasionally the nose of thepawl member misses its proper notch in the ratchet disk, or collideswith the point or nose of one of the teeth of the ratchet disk, and insuch a case the strain thereby produced on the pawl-controlling pin orstud, being resisted by the rigid and unyielding cam edge of theaperture through which the stud projects, is liable to break the stud.My present improvement is designed to and does obviate this possiblesource of injury to the mechanism, and consists broadly in providing asufficiently yielding or resilient guiding and controlling member forthe stud to prevent such injury to the latter in the event of imperfectregistration of the dogs with the ratchet disk. A simple and approvedform of this mechanism is shown herein, more particularly in Figs. 1 and4, in which 45 designates an opening in the side wall of the casing 19that is closed by a cover-plate 46 detachably secured thereto as bymeans of screws 47. In a socket 48 formed in the inner side of the plate&6 is snugly seated the shank 49 of a bent spring, herein shown astwo-ply throughout and having lower and upper limbs 50 and 51 that aresuitably bent or curved to form guiding and controlling surfaces for.the pins or studs 33 and 3t, respectively, the ends of said pins orstuds underlying and engaging the lower edge of the limbs of saidspring.

In operation, remembering that during the lowering of the lifting barthe springs 35 and 36 are constantly tending to throw the pawlsoutwardly or away from the ratchet disk, the action of the yieldingguides 50 and 51 upon the studs is such as to alternately positivelydirect the noses of the pawls into engagement with the notches of theratchet disk just prior to the extreme limits of the up and downmovements of the lever; the spring 35 or 36 operating to throw out thepawl controlled thereby just after the other pawl has been directed intodogging engagement With the ratchet disk by its guides 50 or 51, as thecase may be. In the event that either pawl, upon being forced intoengagement with the ratchet disk, fails to engage the latter properlythrough collision with a tooth of the ratchet disk, the guide 50 or 51,as the case may be, will yield sufficiently to allow the pawl to findits proper engagement, and thus prevent a breaking strain from beingbrought upon the pin or stud.

While I have herein shown a simple bent spring with its two limbsproperly curved to effect the requisite guiding action upon the pawls,yet it will be understood that, within the invention, any other suitableguiding means may be employed, provided it have the yielding characterto obviate injurious strain upon the pins or studs; and hence theinvention is not limited to the particular form of guide shown, exceptto the extent clearly indicated in specific claims.

I claim:

1. In a jack, the combination with a casing, and a lifting bar slidablymounted therein, of an o crating lever pivoted in said casing, a pawcarried by said lever, a ratchet-member adapted to be engaged by saidpawl and operatively connected to said lifting bar, a lateral projectionon said pawl, and a leaf spring secured at one end-to a side wall ofsaid casing and slidably engaged by said lateral projection during themovement of said pawl toward said ratchetmember whereby said pawl isforced into engagement with said ratchet-member upon the actuation ofsaid operating lever, substantially as described.

2. In a jack, he combination with a casing having an opening in its sidewall and a removable cover plate covering said opening, of a lifting barslidably mounted in said casing, an operating lever pivoted in saidcasing, a pawl carried by said lever, a laterally projecting pin carriedby said pawl, a ratchet-member adapted to be engaged by said pawl andoperatively connected to said lifting bar, and a leaf spring secured atits inner end to the inner side of said removable cover plate andslidably engaged at its free outer end portion by said pin during themovement of said pawl toward said ratchet-member whereby said pawl isforced into engagement with said ratchet-member upon the actuation ofsaid operating lever, substantially as described.

3. In a jack, the combination with a casing and a lifting bar slidablymounted therein, of an operating lever pivoted in said casing, a pair ofalternately acting pawls carried by said lever, laterally projectingpins carried by said pawls, a ratchet member adapted to be engaged byboth of said pawls and operatively connected to said lifting bar, springmeans for normally urging said pawls out of engagement with said ratchetmember during the descending movement of the lifting bar, and yieldableresilient guides slidably engaged by said pins during the movement ofsaid pawls toward said ratchet member whereby said pawls are alternatelyforced into engagement with said ratchet member upon the actuation ofsaid operating lever, substantially as described.

4:. In a jack, the combination with a casing and a lifting bar slidablymounted therein, of an operating lever pivoted in said casing, a pair ofalternately acting pawls pivoted to said lever on opposite sides of thepivot of the latter, laterally projecting pins carried by said pawls, aratchet member adapted to be engaged by both of said pawls andoperatively connected to said lifting bar, spring means for normallyurging said pawls out of engagement with said ratchet member during thedescending movement of the lifting bar, and a pair of yieldable springguides secured at one end in said casing, said spring guides having camsurfaces engaged by said pins, respectlvely, during the movement of saidpawls toward said ratchet member whereby said pawls are alternatelyforced into engagement with said ratchet member upon the actuation ofsaid operating lever, substantially as described.

5. In a jack, the combination with a casing having an opening in a sidewall thereof, and a removable plate covering said opening, of a liftingbar slidably mounted in said casing, an operating lever pivoted in saidcaslng, a pair of alternately acting pawls pivoted on said lever onopposite sides of the pivot of the latter, laterally projecting pinscarried by said pawls, a ratchet member adapted to be engaged by both ofsaid pawls and operatively connected to said lifting bar, spring meansfor normally urging said pawls out of engagement with said ratchetmember during the descending movement of the lifting bar, and a bentspring removably secured at its shank in said removable plate and havina pair of limbs provided with cam sur aces slidably engaged by said pinsand operating to alternately force said pawls into engagement with saidratchet member upon the actuation of said operating lever, substantiallyas described.

WALTER B. TEMPLETON.

Witnesses SAMUEL N. Pom), FREDERICK C. GooDwIN.

